Tuesday, 15 February 2011

Elephant's foot a grape

As I've mentioned before, the Royal Botanic Gardens in Sydney has its own vineyard – only six vines but of the very finest Shiraz stock.

Over summer there is another kind of grape in fruit. It’s one of our succulents, and you’ll find it just inside the Cacti and Succulent Garden, to your left.

We call it Elephant’s Foot (not Elephant’s Foot Tree, Elephant Tree or Elephant Ear, which are entirely different plants), a name referring to its stumpy swollen trunk. Fat bottomed plants like this are sometimes called ‘caudiciform’, but that term is better applied to climbers rising out of swollen stem or root. It’s best to call our plant a ‘pachycaul’, like an elephant trunk.

The fleshy stems, and leaves, allow it to store water in the hot dry deserts of Namibia and the west coast of South Africa, where it is now uncommon.

In Africa, Cyphostemma juttae, is also called the Wild or Tree Grape, or more colourfully, the Droog-my-keel and Baster Kobas (or Bastard Cobas).

The small white flowers are nothing to write home about, but the bunches of juicy red grapes are a worthy of a wine-writer’s pen. You can see the family resemblance. Elephant’s Foot is in the Vitaceae, the same family as Vitus, the grape we eat and drink.

Apart from the gorgeous fruits, the bark is quite attractive in older plants – it becomes white and papery, helping to reflect light and keep the plant cool.

Elephant’s Foot is slow growing. Our 20-year-old plant is about waist high at the moment and they can reach up to 2 m tall. Obviously it grows outdoors in Sydney, but it’s important to keep the soil dry (well drained) during the winter months

So can you eat the grapes or make Elephant’s Foot wine? Sadly no, and the fruits are highly toxic.

Image: At top, a bunch of poisonous grapes on the exotic Elephant’s Foot; here, the full plant in fruit. *This posting is from the Radio Archives (February 2009).